1. Field of the Invention
The invention relates to an amphibian bridge-forming and ferrying vehicle, comprising essentially a self-propelled main floating body, two folding lateral floating bodies, and two laterally foldable, hydraulically liftable and lowerable folding ramps, each comprised of a ramp base and a ramp tip.
2. Description of the Related Art
Amphibian bridge-forming and ferrying vehicles are known from German published patent documents 11 24 383 A, 19 49 206 A, 33 42 087 A as well as 33 42 088 A. They are comprised essentially of a main floating body, which comprises the required components for propelling the vehicle on land or on water, and two lateral floating bodies. During propelling on land, the two lateral floating bodies are folded inwardly onto the main floating body in order to provide a narrow road-suitable contour. The vehicle can be driven into the water and move in the water with the lateral floating bodies in the folded position.
When the amphibian vehicle is to be used as a bridge or a ferry, the lateral floating bodies are hydraulically unfolded outwardly by 180 degrees so that a stable floating position and a great carrying capacity can be obtained; in this way, even great weights can be supported thereon.
In addition to the main floating body and the lateral floating bodies, the afore described amphibian vehicles are provided with ramps which enable a comfortable and safe connection from the bank or shore to the amphibian vehicle and from the amphibian vehicle to a neighboring amphibian vehicle. These ramps, when not in use, are stored adjacent and atop one another on the folded lateral floating bodies or in matching cutouts between the main floating body and the folded lateral floating bodies. In order to move the ramps from their transport position in the longitudinal direction of the amphibian vehicle into their position of use in a direction transverse to the transport direction, suitable assisting devices, for example, an on-board crane are provided on the main floating body. For moving the ramps and for operating the on-board crane, several persons are required as operating personnel. They must work on the deck of the amphibian vehicle where they are completely unprotected. This is unsatisfactory.
A further disadvantage of the known solution is that the individual ramp elements are relatively narrow, in particular, have a width less than half the width of the main floating body. This means that on each side of the amphibian vehicle two spaced-apart ramp elements are required when the roadway is needed for carrying heavy vehicles such as trucks or tanks. When it is desired, for safety reasons, to close the gap between the two ramps, additional roadway plates must be inserted which must be transported loosely on the amphibian vehicle.
Initially, those ramps were rigid. However, this limited their length to the length of the amphibian vehicle. In subsequent developments, so-called folding ramps have been used. They are stored in the folded state on the amphibian vehicle when not in use. In the position of use, they can be unfolded so as to have almost twice the length of the amphibian vehicle. Such folding ramps are described in German published patent documents 19 49 206 A, 33 42 087 A, and 33 42 088 A. The configuration described in 19 49 206 A has moreover the advantage that for moving the folding ramps from the transport position into the position of use, an onboard crane is not required because the folding ramps are connected to an upright center part provided on the deck of the main floating body and rotatable about a vertical axis. The folding ramps are comprised of a ramp base, which is connected to the rotatable center part and can be lifted and lowered by means of hydraulic cylinders, and a ramp tip, which is connected to the free end of the ramp base and can be pivoted, also by hydraulic cylinders, about 180 degrees. The hinge between the ramp base and the ramp tip is configured such that the ramp tips rest against the underside of the ramp base in the transport position.
Additionally, an amphibian bridge-forming and ferrying vehicle is being used in which the folding ramps are connected to the front and the rear of the self-propelled main floating body. For increasing the carrying capacity, the ramp bases are provided with their own floating bodies. An advantage of this vehicle is its great length, comprised of the length of the two folding ramps and the length of the main floating body, as well as its great carrying capacity. However, one problem is that the main floating body must have a great width because of the required roadway width for the above-mentioned large and heavy vehicles. Such a wide contour however impedes fast propelling on land and on water. Also, when the ramps are unfolded, the operating personnel practically has no visibility from the cockpit.
It is an object of the present invention to provide an amphibian bridge-forming and ferrying vehicle which combines a narrow transport contour with a great bridge length and high carrying capacity.
In accordance with the present invention, this is achieved in that the vehicle has the following features:
a self-propelled main floating body;
two foldable lateral floating bodies;
two laterally foldable, hydraulically liftable and lowerable folding ramps, each comprised of a ramp base and a ramp tip, respectively;
the folding ramps are connected to the lateral floating bodies;
the ramp tips, when the floating ramp is in the folded position, rest on the topside of the ramp base;
the decks of the main floating body and of the lateral floating bodies form a continuous roadway together with the folding ramps.
The present invention also employs folding ramps which however are connected on the outer longitudinal sides of the unfolded lateral floating bodies. At the same time, the decks of the main floating body and of the lateral floating bodies provide a roadway so that the bridge length with the folding ramps unfolded is correspondingly enlarged. The topside as well as the underside of the folding ramps are used as a roadway. Moreover, almost the entire length of the main floating body is available as a roadway width so that the roadway can be used safely even in the case of problem loads under problematic conditions. When the amphibian vehicle is used as a ferry, a large base surface area is available for transport.
Further advantages of the invention reside in that the ramp tips, in contrast to the prior art, are folded against the topside and not the underside of the ramp base. In this way, in the case of the folding ramp being in the folded position, the complete ramp adjusting travel in the downward direction is maintained and the overload safety provided by the pressure relief valves on the ramps cylinders remains effective.
Since in the vehicle according to the invention the folding ramps in the transport position (folded position) are arranged on the main floating body transversely to the longitudinal direction of the vehicle, they must not be rotated before being unfolded. Also, no loose parts must be handled anymore. In this way, it is possible to control all folding and unfolding steps from the interior of the vehicle, optionally by means of a computer. The operating personnel no longer must leave the protected vehicle area.
According to a first embodiment of the invention, the folding ramps have a wedge-shaped cross-section and the deck of the lateral floating bodies is slanted in a complementary or matching way. In this way, the folding ramps can be placed or stored without gaps on the lateral floating bodies. A planar roadway thus results because of the wedge shape.
As mentioned above, all of the pivoting steps are realized by hydraulic cylinders provided on the vehicle. In special cases, it can however be advantageous when certain elements are rigidly coupled to one another. In this connection, the hinges between the lateral floating bodies and the ramp base or between the main floating body and the lateral floating bodies come to mind. In these cases, rigid coupling brackets can be mounted.
In particular, in the area between the main floating body and the lateral floating bodies, multi-stage, in particular, three-stage coupling brackets were found to be advantageous. In this way, the ramp adjusting stroke can be significantly enlarged for the maximum ramp slant still permitting driving.
It is understood that between the ramp base and the ramp tip detachable hinge couplings must be provided in order to provide a bending-resistant connection of the two elements. These hinge couplings however also provide the possibility of coupling the folded ramps of two neighboring amphibian vehicles with one another in order to provide in this way a ferry of twice the width or a bridge of a corresponding great length.